This invention relates to a highly available computer system which constitutes a cluster configuration in a server virtualization environment, and more particularly to a program which has a function of monitoring failures and executing failover.
Server virtualization is a technology of simultaneously operating a plurality of operating systems (hereinafter, referred to as OS) in a single physical computer. Logical partitioning is realized via a management program (server virtualization program) for dividing resources of the physical computer into a plurality of logical partitions (LPAR), and one OS (guest OS) is operated in each LPAR. The server virtualization program is a program operated in a server virtualization layer (hereinafter, referred to as host OS) such as a hypervisor or an OS different from the guest OS in the physical computer.
In the physical computer (server virtualization environment) which uses such logical partitioning, because the resources of the physical computer are shared by the plurality of LPAR's, there is a possibility that failures will occur in the plurality of LPAR's when the resources of the physical computer fail.
Thus, in the case of constructing a highly available computer system in the server virtualization environment, a cluster configuration computer system which turns over (fails over) an application program (hereinafter, referred to as AP) operated in the guest OS when a failure occurs to another standby system guest OS is used.
In “VMware Server Integral Solution Employing CLUSTERPRO”, online, issued by NEC Corporation, retrieved Oct. 31, 2006, Internet URL: http://www.ace.comp.nec.co.jp/CLUSTERPRO/doc/pp_lin/CLUSTERPRO_VMware.pdf (hereinafter, referred to as Non-patent Document 1), the following cluster configuration methods are realized in the server virtualization environment: a method 1 for operating a cluster program in a guest OS of each LPAR to monitor failures of the guest OS and AP between the guest OS's and to execute AP failover; and a method 2 for operating a cluster program in a host OS to monitor failures of the host OS and the guest OS between the host OS's and to execute guest OS failover.